Effect of Exogenous Nitric Oxide on Postharvest Storage Quality of Hyacinth Bean

In order to study the effect of nitric oxide (NO) on the storage quality of hyacinth bean after harvest, sodium nitroprusside (SNP) was used as an exogenous NO donor in this study. Hyacinth bean was soaked in 0.2 mmol/L SNP solution or distilled water as control for 10 min and then stored at (20 ± 1) ℃ and 80%–90% relative humidity. Decay incidence, rust incidence, hardness, the contents of total soluble solids (TSS), malondialdehyde (MDA), flavonoids, total phenols and chlorophyll, and the activities of antioxidant enzymes (peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammoniase (PAL), catalase (CAT) and ascorbate peroxidase (APX)) were observed during the storage period. The results showed that exogenous NO treatment could inhibit the rot and rust, keep the color and hardness, and inhibit the degradation of TSS and chlorophyll in hyacinth bean, so that hyacinth bean could maintain good sensory quality. Exogenous NO treatment could also prevent the accumulation of MDA and increase the contents of total phenols and flavonoids. In addition, exogenous NO treatment maintained the activities of PAL, CAT and APX during storage, and inhibited the increase in the activities of POD and PPO, thereby enhancing the antioxidant capacity and delaying the maturation and senescence of hyacinth bean. In conclusion, exogenous NO treatment can delay the postharvest maturation and senescence, maintain the physiological quality during storage, and effectively prolong the shelf life of hyacinth bean